<?php
//比较运算符

$a=[true,false,'9','123a'];
foreach ($a as $row) {
    foreach ($a as $col){
        $b=$row == $col; //2.5.6.2 松散比较 ==
        if($b)echo "1\t";
        else echo "0\t";
    }
    echo "\n";
}
//is_numeric
$a=['12','+12','-12','012','0x1a','2e5','2aaa'];
foreach ($a as $value) {
    echo is_numeric($value)?"true":"false","\t";
}
echo "\n";

//2.5.6.3 严格比较 ===
var_dump(123==='123');